I looked into it and the actual answer as with everything it’s extremely complicated and you’re original pithy 80% of IQ is heritable seems to be dependent on how much culture is involved in the testing methodology... https://blogs.scientificamerican.com/beautiful-minds/the-her...

I think the idea that we can control properly is extremely unlikely and IQ will turn out to be a lot difficult to extract from learning/society/environment than you might think, especially as findings with epigenetics and intelligence start to be shown. https://www.europeanscientist.com/en/research/epigenetics-an...